title: Caecal fermentation, putrefaction and microbiotas in rats fed milk casein, soy protein or fish meal.
abstract: To clarify the effect of soy protein (SP) and fish meal (FM), compared to milk casein (MC), on the intestinal environment, we examined caecal environment of rats fed the test diets. Four-week-old rats were fed AIN-76-based diet containing 20 %, w/w MC, SP or FM for 16 days. Caecal organic acids were analysed by HPLC. Caecal putrefactive compounds (indole, phenol, H2S and ammonia) were analysed by colorimetric assays. Caecal microflora was determined by 16S rRNA gene-DGGE and pyrosequencing with bar-coded primers targeting the bacterial 16S rRNA gene. n-Butyric and lactic acid levels were high in rats fed SP and FM, respectively. Butyrate-producing bacteria, such as Oscillibacter, and lactate-producing bacteria, such as Lactobacillus, were detected in each diet group. Also, the putrefactive compound contents were high in rats fed SP and FM. In this study, both DGGE and pyrosequencing analyses were able to evaluate the dynamics of the intestinal microbiota. The results indicate that dietary proteins can alter the intestinal environment, affecting fermentation by the intestinal microbiota and the generation of putrefactive compounds.
authors.affiliation: Department of Food Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo, Japan.
authors.forename: Choa
authors.initials: C
authors.lastname: An
authors.forename: Takashi
authors.initials: T
authors.lastname: Kuda
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yazaki
authors.forename: Hajime
authors.initials: H
authors.lastname: Takahashi
authors.forename: Bon
authors.initials: B
authors.lastname: Kimura
mesh_terms: D000641:Ammonia / Q000032:analysis; D000821:Animal Feed; D000818:Animals; D001419:Bacteria / Q000145:classification / Q000235:genetics; D058448:Biota; D002264:Carboxylic Acids / Q000032:analysis; D002364:Caseins / Q000378:metabolism*; D002432:Cecum / Q000737:chemistry / Q000382:microbiology*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004032:Diet / Q000379:methods*; D005285:Fermentation; D005399:Fishes / Q000378:metabolism*; D006862:Hydrogen Sulfide / Q000032:analysis; D007211:Indoles / Q000032:analysis; D008969:Molecular Sequence Data; D019800:Phenol / Q000032:analysis; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D051381:Rats; D017422:Sequence Analysis, DNA; D030262:Soybean Proteins / Q000378:metabolism*
chemical_list: D002264:Carboxylic Acids; D002364:Caseins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D007211:Indoles; D012336:RNA, Ribosomal, 16S; D030262:Soybean Proteins; D019800:Phenol; D000641:Ammonia; C030374:indole; D006862:Hydrogen Sulfide